Even bigger coin ID please?

[Kapidr]

Here's another found today. ID Please?

 

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[Mackaydon]

If the diameter is 34 MM it's a 4R; if 40 MM, it's an 8 R; Mexican; Carlos IV; assayer FM--IMO
Cleaning will answer questions.
Don.......

 

[Kapidr]

If the diameter is 34 MM it's a 4R; if 40 MM, it's an 8 R; Mexican; Carlos IV; assayer FM--IMO
Cleaning will answer questions.
Don.......

Thanks again Don! Working to clean it now, 8 it is My first!

 

[Iron Patch]

If you are using electrolysis, stop and try lemon juice! You will be eating away the surface and it looks like it will clean great with a lemon soak.

 

[huggis]

Great finds nice work on the I.D. Guys as always!!!

 

[Kapidr]

If the diameter is 34 MM it's a 4R; if 40 MM, it's an 8 R; Mexican; Carlos IV; assayer FM--IMO
Cleaning will answer questions.
Don.......

It's closer to 38 mm. Here it is cleaner.

 

[Mackaydon]

Mexican coins are not minted over the standard diameter, so you coin is an 8R; even if the '8' were not visible--though it is.
No question as to what you have: 1788 Mexico City Mint 8R, 0.9027 fine silver, FM assayer;series minted between 1773 and 1789 (probably ~26 grams).
Don..........

 

[Kapidr]

Mexican coins are not minted over the standard diameter, so you coin is an 8R; even if the '8' were not visible--though it is.
No question as to what you have: 1788 Mexico City Mint 8R, 0.9027 fine silver, FM assayer;series minted between 1773 and 1789 (probably ~26 grams).
Don..........

23.8 grams Thanks Don!